The potential of agricultural waste materials for the removal bisphenol A (BPA) from aqueous solution was investigated. BPA is an endocrine-disrupting compound (EDC) used mainly in the plastic manufacturing industry. It may be hazardous to humans and animals because of its estrogenic activity. Agricultural wastes are sustainable adsorbents because of their low cost and availability. Hence, this study investigated the removal of BPA from water by adsorption onto treated coir pith, coconut shell and durian peel. The adsorption of BPA from water onto adsorbent was evaluated using field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET). The effects of morphology, functional groups, and surface area on adsorption before and after pretreatment with sulfuric acid and reaction were investigated, and it was found that the treated adsorbent were able to remove BPA. Carbonyl and hydroxyl groups had appear in large number in FTIR analysis. The present study indicates that coir pith had removed 72 % of BPA with adsorption capacity of 4.308 mg/g for 24 h, followed by durian peel (70 %, 4.178 mg/g) and coconut shell (69 %, 4.159 mg/g). The results proved that these modified phyto-waste were promising materials as alternative adsorbent for the removal of BPA from aqueous solution.

This study explored the low-cost adsorbent of durian peel for BPA removal from aqueous solutions. The effect of various operational parameters such as contact time, temperature, concentration, agitation and pH on the adsorption of BPA was investigated using the batch adsorption study. It was found that Durian peel can be used as a low cost adsorbent for the removal of BPA in aqueous solution after treated with sulfuric acid. The effects of morphology, functional groups, and surface area of adsorbent, before and after pretreatment with sulfuric acid and reaction were investigated by using FESEM, FTIR, and BET. The present study indicates that durian peel had removed 69.63% of BPA with adsorption capacity of 4.178 mg/g for 24 hours. The result proved that this treated agricultural waste was promising material as an alternative adsorbent for the removal of BPA from aqueous solution. Kinetic study of the results gave a pseudo-second order type of mechanism while the adsorption characteristics of the adsorbent followed the Langmuir adsorption isotherm.

Cresol Red belongs to the triphenylmethane (TPM) class of dyes which are potentially carcinogenic or mutagenic. However, very few studies on biodegradation of Cresol Red were investigated as compared to other type dyes such as azo and anthraquinone dye. The aim of this work is to evaluate triphenylmethane dye Cresol Red degradation by fungal strain isolated from the decayed wood in Johor Bahru, Malaysia. Detailed taxonomic studies identified the organisms as Trichoderma species and designated as strain Trichoderma harzianum M06. In this study, Cresol Red was decolorized up to 88% within 30 days under agitation condition by Trichoderma harzianum M06. Data analysis revealed that a pH value of 3 yielded a highest degradation rate among pH concentrations (73%), salinity concentrations of 100 g/L (73%), and a volume of 0.1 mL of Tween 80 (79%). Induction in the enzyme activities of manganese peroxidase, lignin peroxidase, laccase, 1,2- and 2,3-dioxygenase indicates their involvement in Cresol Red removal. Various analytical studies such as Thin-Layer Chromatography (TLC), UV-Vis spectrophotometer, and Gas chromatography mass spectrometry (GC-MS) confirmed the biotransformation of Cresol Red by the fungus. Two metabolites were identified in the treated medium: 2,4-dihydroxybenzoic acid (t R 7.3 min and m/z 355) and 2-hydroxybenzoic acid (t R 8.6 min and m/z 267). Based on these products, a probable pathway has been proposed for the degradation of Cresol Red by Trichoderma harzianum M06.

This study explored the low-cost adsorbent of orange peel and spent tea leave for Methylene Blue (MB) and Remazol Brilliant Blue R (RBBR) dyes removal from aqueous solutions. The removal rate and adsorption capacity on the adsorption of dyes were investigated using the batch adsorption study. The present study indicates that the MB was easier to remove by both orange peel and spent tea leave compared to RBBR with percentage removal of 95.72 % and 99.02 % respectively. The effects of morphology, functional groups, and surface area of adsorbents were investigated by using FESEM, FTIR, and BET. The result proved that orange peel and spent tea leave were promising material as an alternative adsorbent for the removal of MB from aqueous solution.

An oil palm empty fruit bunch-derived activated carbon has been successfully produced by chemical activation with zinc chloride and without chemical activation. The preparation was conducted in the tube furnace at 500oC for 1 h. The surface structure and active sites of activated carbons were characterized by means of Fourier transform infrared spectrometry and field emission scanning electron microscopy. The proximate analysis including moisture content, ash content, bulk density, pH, and pH at zero charge was conducted to identify the psychochemical properties of the adsorbent. The results showed that the zinc chloride-activated carbon has better characteristics compared to the carbon without chemical activation.